Phonographic driving mechanism.



0. F. ROBERTS.

PHONOGRAPHIC DRIVING MECHANISM.

APPLICATION FILED AUG.23.1917.

2 SHEETSSHEET l.

217423686 6; 7 Inventor h r .fioberp y My 34- Patented Feb. 4,1919.

- (1.. F. ROBERTS PHONOGRAPHIC DRIVING MECHANISM.

APPLICATION FlL ED AUG.23, I917- Patented Feb. 4,1919.

2 SHEETS-SHEET 2. 4

v UNITED STATES PATENT OFFICE.

CHARLES F. ROBERTS, OF CHICAGO, ILLINOIS, ASSIGNORTO CHICAGO METALPRODUCTS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION 0Fv ILLINOIS.

PHONOGRAPHIC DRIVING MECHANISM.

Specification of Letters Patent.

To all whom it may concern:

Be it known that I, CHARLES F. ROBERTS, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented a certain new and useful Improvement in PhonographicDriving-Mechanism, of which the following is a full, clear, concise, andexact description, reference being had to the accompanying drawings,forming a part of this specification.

My invention. relates to phonographic driving mechanism, and has for itsgeneral object the provision of mechanism for driving the record turntable of a phonograph, which is noiseless in its operation and whichrequires comparatively little lubrication for operation.

In accomplishing thiseneral object I eliminate the usual form of gearingextending between the driving element and the turn table, and utilize inits place a novel arrangement of friction transmission, which, in thepreferred form ofv the invention is self-adjusting andrequires no manualadextending above the base board 4: has fixed justment afterinstallation.

Considerable objection has been met in the past in the use of anelectric motor, particularly an alternating current motor forphonographs, due to the hum of the motor while a selection is beingreproduced by the honographic mechanism, and because of tiiis objectionthe electrically driven phonograph has not met with the success it mighthave attained, notwithstanding its otherwise I11 merous advantages overthe spring driven motor. It is one of the objects of the presentinvention to provide an electrically driven phonograph which isabsolutely silent in its operation, even though an alternating currentmotor be employed. A further object of the inventionis the provision ofa novel arrangement of parts, constitut ing the transmission mechanismextending between the driving element and the turn table, all of whichwill be pointed out in detail in connection with the accompanyingdrawings, wherein Figure l is a front elevational View of a phonographicbase board or motor board provided with the turn table and drivingmechanism of my invention, some of the .parts being broken away torevealimore clearly the internal construction;

'just referred to of flexibility in the f it may operate properlytc-dnve the turn Fig. 2 is-an enlarged detail view of the transmissionmechanism extending between the electric motor and the turn table; and

Fig. 3 is an enlarged detail view showing the resilient mounting betweenthe electric usual base board or motor board commonly used in'connectionwith phonographic constructions, which is arrangedto be held in placeupon the phonographic cabinet. Attached to the under side of the baseboard 4 by means of screws, one of which is illustrated at 5, is abracket 6 having two depending arms 7 7 attached thereto and connectedat their lower ends by the plate 8. Journaled in the bracket 6. and theplate 8, and extending upwardly through the base board 4 is a shaft 9,to which is keyed a wheel 10, preferably constructed of metal. The shaft9 above the wheel 10 is provided with the centrifugal speed governormechanism shown at 11. The end of the shaft 9 thereto a resilientfriction Wheel 12, most clearly shown ,in Fig. 2. This wheel is arrangedto have frictional driving connection with the inside face of thedownwardly extending peripheral flange 13 provided on the turn table 14.The upper face of the turn ture 17 provided in the base board, and isarranged to have movement in a plane normal to its axis. A spring isemployed at 18 which tends to move the shaft 16 in a direc- PatentedFeb. 4, 1919.

tion away from the shaft 9, so that the inside face of the depending,flange on the turn table is held in frictional en agement with thewheel 12 at all times. he mechanism for maintaining the frict'ional.connection between the turn table and the friction wheel forms no partof the present invention, and is disclosed and claimed in my copendingapplication Serial No. 117,172,- filed August as, 1916.

In order to provide therequisite amount friction wheel 12 so that table,the wheel is provided with the under-' cuts shown at 19 and 20 in Fig.2. This wheel. is preferably constructed of soft'vulcanized rubber, andbecause of this undercut arrangement, it is caused to drive the turntable without slippage.

Attached to the under side of the bracket 6 is an electric motor 20,preferably a motor adapted to run on alternating as well as directcurrent, which is .connected to the bracket6 in a manner such that thetrans- 'mission of vibration is prevented from the motor to the bracket6, and thus to the base board 4:. To prevent such transmission of sound,resilient mountings are provided he tween the' motor and the bracket 6,and in Fig. 3 I have shown two of suchmountings in detail, there beingfour provided in the preferred arrangement. Inthis figure I have shownat 21 and 22 a pair of resilient I mountings. The mountings are alike incon- The upper side of the bracket 6 is providedstruction, and it willbe necessary, therefore, to describe only one of them. The motor 20carries a base 23 provided with an aperture 24 in substantial alinementwith. an aperture 25 inthe bracket 6. Extending into the apertures 24and 25. of the motor 23 and bracket fi'respectively .is a rubber collar26 provided with an enlarged portion 27, which serves to space the motorfrom the bracket.

with'a depression in which is disposed a rubber block 28. a A similarrubber block is utilized at 29- on the under side-of the motor callyextending shaft 9;

base 23. Extending vertically through the rubber mountings. 26, 28 and29 is a screw-30 which holds the parts in place.

The armature shaft-of the electric motor 20 is connected at its outerend with a flexible wheel 31,- which has its periphery indriving'engagement with the flat face of the wheel 10'. The flexiblewheel 31 is undercut as shown at 32, so that it contains the requiredamount of flexibility to provide aneflicient driving connection betweenthe. armatureshaft of the motor and the verti- It will be seen from theabove that the electric motor is rendered absolutely noiseless in thatsound cannot be transmitted from the motor through its mountings or fromthe motor through the armature shaft and transmission mechanism, due tothe flexible wheels employed, at 12 and 31.

Due to the PIOVlSlOIl of the flexible wheel 31'- and the. flexiblemounting of the motor,

the wheels 10 and 31 are maintained in driv-- ing relation at all times.In assembling the device the motor is first hung as described,

so that its armature shaftlies'in a substantially horizontal plane? Thewheel -10 is then placed in position tightly against the flexible wheel31. with the result that the flexible motor mountings on the left-handside (Fig. 1).are slightly compressed and the motor shaft slightlytilted away. from the horizontal. The left-hand end of the motor(Fig. 1) thereby has a tendency to move downwardly, and because of thistendency the required frictional engagement between the wheels 10 and 31is maintained. I also wish to call attention to the fact that althoughthe motor mounting is extremely flexible, it is such that it cannot beharmed nor can the parts of the motor be broken or moved out of placeduring shipment' Having thus described my invention, what I claim as newand desire to secure by Letters Patent ofthe United States is:

1. A phonograph c'omprising a base board, a turn table on the upper sidethereof, an electric motor on the under side of the base board,resilient means for mounting the moresilient driving mechanism betweenthe m tor and the turn table. 1

. 3. A phonograph structure including a record turn table having adepending p'eripheral flange and a resllient friction dr ving wheelhaving driving connection with the said flange, said wheel beingundercut toprovide the, requisite amountof flexi- 4. Driving mechanismfor .phonographs, including a frictional driving connection comprising adriving member and a drlven member, one of said members comprising aflexible wheel having one of its faces undercut to provide the requisiteamount of flembility.

' 5. A-phonograph comprising a base board,

a record turn table on t e upper-side thereof, said turn table beingprovlded with a depending peripheral flange, a driving shaft extendingupwardly throu h the base board,

.and a flexible' 'friction w eel fixed to the shaft andengaging theinner face of the dependin annularflange, said wheel. having one'ofltsflat faces provided with an undercut to render it of sufficientfiexlbihtyfor proper operation. I

6. In a phonograph the combmation W1th a base board of amotor,'headedmembers for securing the motor to the base board,"

and rubber mountings interposed between the motor and thebase board andbetween the motor and the heads of saidheaded members. i j 7. Aphonographcomprising a base board,

i a. turn tablerotatably mounted in said base board, means for drivingsaid turn table, comprising a friction, disk, a motor pivotally mountedto swing in a plane extending at an angle to the plane of the disk andprovided with a resilient drive wheel. contacting with said disk, andresilient means for urging said drive wheel against the surface of saiddisk. 7

8.- A phonograph comprising a'base board, a turn table rotatably mountedin said base board, means for driving said turn table, comprising afriction disk, and a motor pivotally mounted to swing in a planeextending at an angle to the plane'of the disk and provided with aresilientdrive' wheel contacting with said disk. I

9. A phonograph com rising a base board,

a record turn table on the upper side theredercut to render it ofsufiicient flexibility for a proper operation. I

10. A. phonograph comprising a base board, an electric motor on theunder side. of the base board, a pair of rubber blocks for mounting themotor on the base board so as to prevent the transmission of. vibrationfrom the motor to the base board, said blocks being spacedlongitudinally of the motor, a friction wheel mounted on the armatureshaft of the motor, and a second friction wheel having driven engagementwith the firstwheel, the disposition of the second Wheel being such asto provide compression of one of the A said mountings, whereby the motorhas a tendency to maintain the required frictional engagement of thewheels.

In witness whereof I hereunto subscribe my name this 20th day of August,A. D. 1917.

CHARLES F. ROBERTS. WVitnesses i V ANDREW WINTERCORN, n MARY A. CooK.

